/Engine/Source/Editor/UnrealEd/Public/Subsystems/AssetEditorSubsystem.h
Tries to open an editor for all of the specified assets. If any of the assets are already open, it will not create a new editor for them. If all assets are of the same type, the supporting AssetTypeAction (if it exists) is responsible for the details of how to handle opening multiple assets at once.
bool OpenEditorForAssets_Advanced ( const [TArray](API\Runtime\Core\Containers\TArray)< [UObject](API\Runtime\CoreUObject\UObject\UObject) * > & InAssets, const [EToolkitMode::Type](API\Editor\EditorFramework\Toolkits\EToolkitMode__Type) ToolkitMode, [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [IToolkitHost](API\Editor\EditorFramework\Toolkits\IToolkitHost) > OpenedFromLevelEditor, const [EAssetTypeActivationOpenedMethod](API\Developer\AssetTools\EAssetTypeActivationOpenedMethod) OpenedMethod )